A new synthetic approach is described for building the coumarin scaffold through the Lewis acidpromoted
cyclization of novel aryl 3-(dimethylamino)prop-2-enoates 2a – 2f. The latter precursors were
prepared via aminomethylenation of the corresponding aryl acetates 4a – 4f with the Bredereck reagent.
This approach was used for the synthesis of biologically active natural compounds 1a – 1f, through a
three-step procedure starting from the corresponding phenols.

Descripción :

New Approach for the Construction of the Coumarin Frame and Application in the Total Synthesis of Natural Products